Solving for a & b: Increasing GP Equations

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In summary, the problem asks to find the values of a and b when x_1, x_2, x_3, and x_4 are the roots of two quadratic equations and are in increasing geometric progression. However, the given equations and information are not sufficient to solve for a and b. The increasing geometric progression means that x_1 < x_2 < x_3 < x_4, and the common ratio is greater than 1.
  • #1
utkarshakash
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Homework Statement


If [itex]x_1,x_2[/itex] are the roots of [itex]x^2-3x+a=0[/itex] and [itex]x_3,x_4[/itex] are the roots of the equation [itex]x^2-12x+b=0[/itex] and [itex]x_1,x_2,x_3,x_4[/itex] are in increasing G.P., find a and b

Homework Equations



The Attempt at a Solution


[itex]x_1+x_2=3 \\
x_1x_2=a \\
x_3+x_4=12 \\
x_3x_4=b[/itex]

But these are not sufficient to find a and b. Also what is meant by an increasing G.P.?
 
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  • #2
utkarshakash said:

Homework Statement


If [itex]x_1,x_2[/itex] are the roots of [itex]x^2-3x+a=0[/itex] and [itex]x_3,x_4[/itex] are the roots of the equation [itex]x^2-12x+b=0[/itex] and [itex]x_1,x_2,x_3,x_4[/itex] are in increasing G.P., find a and b

Homework Equations



The Attempt at a Solution


[itex]x_1+x_2=3 \\
x_1x_2=a \\
x_3+x_4=12 \\
x_3x_4=b[/itex]

But these are not sufficient to find a and b. Also what is meant by an increasing G.P.?
G.P. = Geometric Progression

http://en.wikipedia.org/wiki/Geometric_progression
 
  • #3
utkarshakash said:
But these are not sufficient to find a and b. Also what is meant by an increasing G.P.?

It means that the common ratio of the GP is greater than 1.
 
  • #4
Pranav-Arora said:
It means that the common ratio of the GP is greater than 1.

This means that [itex]x_1<x_2<x_3<x_4[/itex]
But what is the use of this in my question?
 
  • #5
utkarshakash said:
This means that [itex]x_1<x_2<x_3<x_4[/itex]
But what is the use of this in my question?

Ignoring that detail for the moment, simply try answer the question and then you'll see.
 

FAQ: Solving for a & b: Increasing GP Equations

How do you solve for a and b in a GP equation?

To solve for a and b in a GP (geometric progression) equation, you can use the formula a(r^n-1)/(r-1), where a is the first term in the sequence, r is the common ratio, and n is the number of terms. You can also use algebraic methods, such as setting up a system of equations or using logarithms.

Can a GP equation have more than one solution for a and b?

Yes, a GP equation can have multiple solutions for a and b. This is because there are different combinations of a and b that can produce the same sequence of numbers, as long as they follow the same pattern of increasing by a common ratio.

What is the significance of solving for a and b in a GP equation?

Solving for a and b in a GP equation can help us understand the underlying pattern or relationship between the terms in the sequence. It can also help us predict future terms in the sequence or find missing terms.

How is solving for a and b in a GP equation useful in real-life applications?

GP equations can be used to model real-life situations, such as population growth, compound interest, or radioactive decay. By solving for a and b, we can make predictions and analyze trends in these scenarios.

Are there any limitations to solving for a and b in a GP equation?

One limitation is that the formula for finding a and b only works for finite GP sequences, meaning that there is a set number of terms in the sequence. It also assumes that the common ratio is constant throughout the entire sequence, which may not always be the case in real-life situations.

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